Life in soil pores: open windows to soil functioning

Soil pores host dynamic microhabitats where microorganisms interact with organic matter under the influence of soil structure and moisture. The spatial arrangement of pores governs the accessibility of substrates to microbes, modulating decomposition rates and carbon stabilization. Recent studies reveal that microbial activity and carbon use efficiency vary systematically with pore size and connectivity across soil types. Soil moisture, by shaping pore-scale connectivity and diffusion, further influences microbial responses, including priming and the Birch effect. Integrating pore-scale biogeography with moisture dynamics provides a mechanistic understanding of the stabilization and destabilization of soil organic matter. This review synthesizes recent advances in imaging, microscale modeling, and isotopic tracing, highlighting the need to incorporate structural indicators into carbon models. Understanding the interplay between soil architecture, water, and microbial activity is crucial for predicting soil function in a changing climate.